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چکیده
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In this paper, a Doherty power amplifier (DPA) is proposed consisting of class-E as the main branch and class-D as the auxiliary power amplifier (PA). Past matching network is applied in the proposed DPA to control the output impedance and reduce its deviation from matching point, which provides improved bandwidth characteristic. The use of λ/4 lines for inductor modeling, employing power divider and input/output matching networks based on micro-strip stubs result in size reduction of proposed DPA, better isolation of the ports and lower return loss. The proposed Doherty structure is based on class-E in main branch and class-D in auxiliary branch, which provides high efficiency, and high output power in 2.7–3.5 GHz frequency band. The proposed DPA has drain efficiency of 65.4% and the gain of 18.6 dB in P-1dB point (27 dBm input power) where in this point, the output power is 45.87 dBm. In the saturation region, the output power of 48.6 dBm and drain efficiency of 93.7% can be obtained in the proposed DPA as shown in simulation results.
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